Wheel spoke



FIG. 1 is a front perspective view of a wheel spoke showing my new design;

FIG. 2 is a front view thereof;

FIG. 2 is a left side view thereof; and,

FIG. 4 is a right side view thereof.

The broken line showing of environment is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a wheel spoke, as shown and described. 